Water gardening is a subject that I have very little knowledge of but thought many readers might enjoy learning about so I asked Mark Best of Garden Pond Advice to write a guest post on water plants. Water gardening is not a new subject but it is becoming increasingly popular in the everyday backyard garden. I hope you enjoying reading Mark's information about water lilies! ~ Dave

Water lilies, (Nymphaea) have been engaging the imaginations of people for thousands of years. They originate in the dark mud of a pond or lake and rise to exquisite blossoms with beautiful colours for several days before receding back into the depths. In centuries past, they were only seen in palaces and botanical gardens but today you can have their glory in your own back garden.

They come in two types, hardy water lilies and tropical water lilies. Hardy water lilies have been given that name for a reason. They are tough and easy to grow because they need almost no attention by the gardener and continue to bloom all summer. They are day bloomers, depending on the temperature of the water, sunlight and time of year. Just be sure to prune the dead leaves and flowers. Tropical water lilies need more care but are worth it. They bloom in brighter colours and at night, but they need a constant water temperature of 70 degrees F and the tubers have to be taken from the water and stored for the winter.

In a wide and shallow lily basket, which will be put in the bottom of your pond, place the soil. Line the basket with hessian so the soil doesn’t leak out and foul the water. The soil mix should be one part sand, three parts heavy soil, not light potting mix, you can buy this ready made from all good aquatic outlets. Put enough gravel for a 1 – 2 inch covering on top to keep the soil from rising out of the pot. Plant the tuber along the side of the pot with the growing tip pointing towards the center of the pot and cover it with the gravel. Now it is ready to be put into 18 to 30 inches of water in your pond, but ensure that you can see the plant, if you cant see it, it isn’t getting enough light! If the leaf stems are short place the plant on bricks so it is visible, then lower it slowly as it grows.

Water lilies need at least six hours of full sunlight and calm water. If you have a small waterfall make sure the plants are not near it and the leaves are not being splashed with water. You need to feed your water lilies if you want them to bloom. One way is commercial pond pellets which work well and only need to be given once a month; one tablet in each quarter of the pond. Poke them into the soil in the pot and fill the hole so they stay in the soil. It’s best to do this after the water has become warm and the leaves have started showing. Packing compost into the bottom of the pot is also a good way to feed them but you need to make sure it is compacted well, at least an inch think, then cover it with the soil. Sometimes it leaches into the water and will help algae grow, but this should clear up as soon as the water gets warm in the spring.

Crown rot is a possible disease that will spoil your water lilies. Prevention is the best remedy because once it starts, it is almost impossible to stop. It will help prevent the disease if the plants are fed well and the dead leaves and flowers are removed, including any soft spots on the tubers and roots. You can also soak them in a separate tub, in a solution of 4 – 6 Tbsp potassium permanganate in 12 - 13 gallons of water for 1 – 2 hours. Cull or remove any diseased plant before it spreads to the others.